Hammer



FIG. 1 is a front, right side and top perspective view of a hammer showing the claimed design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a rear, left side and bottom perspective view thereof.

The dashed broken lines in the drawing depict portions of the hammer that form no part of the claimed design. 

CLAIM The ornamental design for a hammer, as shown and described. 